Tetrahydrofuran (“THF”) and related compounds are useful as solvents and as intermediates in the preparation of industrial chemicals used as pharmaceuticals, herbicides and polymers. For example, tetrahydrofuran is used to make polytetramethylene glycol, which may in turn be used to make polyether ester elastomers and polyurethane elastomers.
“Sponge” metal catalysts such as Raney® nickel catalysts have been used to catalyze the hydrogenation of furan to produce tetrahydrofuran, as discussed e.g. in U.S. Pat. No. 2,846,449. In some instances, the catalyst has been promoted with a small amount of an additional catalytically-active metal such as chromium, as discussed in “Tetrahydrofuran II, Kinetics of Hydrogenation of Furan”, Wang et al in K'o Hsueh T'ung Pao (1958) pages 434˜5; and “Tetrahydrofuran III, High Pressure Hydrogenation of Furan”, Jen et al in K'o Hsueh T'ung Pao (1958) pages 435˜7.
There nevertheless remains a need for catalytic hydrogenation processes to produce tetrahydrofuran, and related compounds, that have greater commercial viability.